Development and characterization of an electrochemical biosensor for creatinine detection in human urine based on functional molecularly imprinted polymer

In this work, sensor based on a new molecularly imprinted polymer (MIP) for creatinine (Cre) detection, using screen-printed gold electrodes (Au-SPE), was developed. A carboxylic polyvinyl chloride (PVC-COOH) layer was first deposited on Au-SPE surface. The creatinine molecules were attached to the surface of Au-SPE/PVCCOOH. Afterward, the polymerization of acrylamide and N, N' methylenebisacrylamid filled vacant spaces around them. The subsequent templates removal left binding sites within the polymer which are capable of selectively recognizing creatinine at different concentrations. To test the sensitivity of this biosensor, the same procedure without creatinine was performed on a gold non-imprinted polymer (Au-SPE/NIP). Their retention and molecular-recognition properties were qualitatively investigated by means of three instrumental techniques: voltammetry (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)), electrochemical impedance spectroscopy (EIS), and UV-Visible spectrophotometry (UV-Vis). The obtained results indicate that the MIP had a specific recognition ability for creatinine, while other structurally related compounds, such as urea or glucose, could not be recognized on the MIP. In addition, the biosensor was tested on volunteers with different creatinine urine levels and seemed a promising tool for screening creatinine in point-of-care. Moreover, Partial Least Square (PLS) analysis was used to obtain a correlation between the predicted creatinine concentrations from voltammetric measurements and concentrations measured by Jaffe's reaction as a reference method. The EIS and DPV biosensor responses show a limit of detection of 0.016 ng/mL and 0.081 ng/mL, respectively, with a linear range from 0.1 ng/mL to 1 mu g/mL. This study provides a promising strategy to fabricate sensor devices based on MIP with highly selective recognition ability, simplicity of operation, small size and low cost. Published by Elsevier B.V.